Co-extrusion of periodically modulated structures

Abstract

A method of forming an extruded structure includes dispensing at least a first material through an extrusion head, varying a pressure applied during extrusion of the first material over time, and depositing the first material on a substrate, wherein a width of the first material varies with a pressure forming a stripe of the first material having a varying width along a length of the stripe.

What is claimed is: 
     
         1 . A method of forming an extruded structure, comprising:
 dispensing at least a first material through an extrusion head;   varying a pressure applied during extrusion of the first material over time; and   depositing the first material on a substrate, wherein a width of the first material varies with a pressure forming a stripe of the first material having a varying width along a length of the stripe.   
     
     
         2 . The method of  claim 1 , wherein varying a pressure comprises modulating a spool valve motor over time. 
     
     
         3 . The method of  claim 1 , wherein varying a pressure comprises modulating a piston drive over time. 
     
     
         4 . The method of  claim 3 , wherein modulating a piston drive comprises modulating a rotary motor over time. 
     
     
         5 . The method of  claim 4 , wherein modulating the rotary motor over time comprises modulating a cam attached to the rotary motor over time. 
     
     
         6 . The method of  claim 3 , wherein modulating a piston drive comprises modulating a linear, moving coil actuator. 
     
     
         7 . The method of  claim 1 , wherein dispensing at least a first material through an extrusion head comprises dispensing a first material and a second material. 
     
     
         8 . The method of  claim 7 , wherein dispensing the first and the second material comprises:
 modulating pressure over time for the first material in a first pattern; and   modulating pressure over time for the second material in a second pattern, wherein the second pattern is complementary to the first pattern.   
     
     
         9 . The method of  claim 8 , further comprising removing the second material. 
     
     
         10 . The method of  claim 9 , further comprising filling a space left by removal of the second material with another material. 
     
     
         11 . The method of  claim 9 , wherein the first pattern has wider and narrower portions and the second pattern has narrower portions that match the wider portions in the first pattern and the second pattern has wider portions that match the narrower portions of the first pattern. 
     
     
         12 . The method of  claim 1 , wherein dispensing at least a first material through an extrusion head comprises dispensing the first material, a second material and a third material. 
     
     
         13 . The method of  claim 1 , further comprising performing the dispensing, varying and depositing with the extrusion head at a first position and repeating the dispensing, varying and depositing with the extrusion head at a second position. 
     
     
         14 . The method of  claim 13 , wherein the second position is adjacent the first position one of either horizontally or vertically. 
     
     
         15 . The method of  claim 12 , wherein the first and third materials have patterns that are in phase, and the second material has a pattern that is complementary to the patterns of the first and third material. 
     
     
         16 . The method of  claim 1 , wherein the varying width has a periodic pattern along the length. 
     
     
         17 . The method of  claim 1 , wherein the periodic pattern is a sinusoidal pattern. 
     
     
         18 . The method of  claim 1 , wherein the varying width has a randomized pattern along the length. 
     
     
         19 . The method of  claim 1 , wherein the first material is electrochemically active. 
     
     
         20 . The method of  claim 19 , wherein the first material forms at least a portion of a battery electrode.